1. Field of Invention
The present invention relates to a power factor correction converter. More particularly, the present invention relates to a power factor correction converter having low conduction losses.
2. Description of Related Art
FIG. 1A depicts a power factor correction converter 100 according to the prior art. As shown in FIG. 1A, when a switch SW1 is turned on, a power factor correction inductor L11 stores energy through a bridge rectifier 110. Conversely, when the switch SW1 is turned off, the power factor correction inductor L11 releases energy to an output capacitor C01, through a diode D01. To put it simply, three semiconductor devices (such as diode) are turned on when the power factor correction inductor L11 stores or releases energy, thus conduction losses of the power factor correction converter 100 are increased.
FIG. 1B depicts a bridgeless power factor correction converter 120 according to the prior art. As shown in FIG. 1B, during the positive half cycle of voltage of the AC power VAC, a switch SW12 is kept being turned on and a switch SW11 and a diode D11 are selectively conducting. During the negative half cycle of voltage of the AC power VAC, the switch SW11 is kept being turned on and the switch SW12 and a diode D12 are selectively conducting. Under the circumstances, high frequency switching AC signals are generated between terminals of the AC power source VAC and the output voltage thus results in increased common mode noise of the power factor correction converter 120. Typically, an electromagnetic interference filter is disposed between the AC power source VAC and the power factor correction converter 120 to reduce common mode noise. However, with such a configuration, the total power consumption is increased and thus increases the conduction losses of the power factor correction converter 120.
In order to solve the aforementioned problems, those skilled in the art are striving to find a solution, but no applicable method has yet been put forward. Therefore, there is a need to reduce conduction losses while reducing common mode noise in a power factor correction converter.